package homework;

import org.junit.Test;

public class ExtendConstract {
    @Test
    public void test(){
Coo coo=new Coo();
Coo c2=new Coo("测试");

    }
}
class Poo{
    public Poo(){
        System.out.println("Poo无参数构造器");
    }
}
class Coo extends Poo{
    public Coo(){
        super();
        System.out.println("Coo无参数构造器");
    }
    public Coo(String data){
        System.out.println("Coo有参数构造器");
    }
}
